Hi Anis, KCM is under very active development. ACIS and Parasolid are limited and fussy in many ways, they have an old code base and have many limitations. Parasolid for example has very stringent requirements on how accurate geometry has to be in order for it to be accepted by the kernel. That may sound good under some concept of "accuracy is good" but in practice it means it's not particularly flexible. I'm not familiar really with C3D but I worry there about support and communication with the development happening very far away from me in a different country. KCM seems to have the most modern code base and has the most potential for continued progress.

I still have yet to see how things will work out, but a while ago I already spent a chunk of time evaluating Parasolid and found it too finicky on what imported geometry it would accept particularly with closed surfaces. It might be a somewhat different matter if everything was constructed in it from the very beginning but I'd like to have a very high amount of compatibility with existing geometry and not have older models rejected by the kernel because a closed surface has a 0.1 degree deviation at its seam for example.

So yes indeed there is a lot to consider and I have been doing just that.

Also ACIS and Parasolid are run by these sort of giant corporate machines which are very annoying to deal with. They only seem to care about dealing with other big corporate entities. With KCM on the other hand I've been able to meet directly with the head of development and they are much more pleasant to work with. It seems to be a much better fit for me. I won't know more until I get to that stage of my v4 development cycle, I'm not quite there yet.

- Michael